US20160376158A1 - Submicron-sized particles including aluminum - Google Patents
Submicron-sized particles including aluminum Download PDFInfo
- Publication number
- US20160376158A1 US20160376158A1 US15/039,824 US201415039824A US2016376158A1 US 20160376158 A1 US20160376158 A1 US 20160376158A1 US 201415039824 A US201415039824 A US 201415039824A US 2016376158 A1 US2016376158 A1 US 2016376158A1
- Authority
- US
- United States
- Prior art keywords
- chemical element
- reaction
- reaction stream
- stream
- chamber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000002245 particle Substances 0.000 title claims abstract description 117
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims description 44
- 229910052782 aluminium Inorganic materials 0.000 title claims description 44
- 238000006243 chemical reaction Methods 0.000 claims abstract description 236
- 229910052729 chemical element Inorganic materials 0.000 claims abstract description 142
- 230000003993 interaction Effects 0.000 claims abstract description 41
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 32
- 239000010703 silicon Substances 0.000 claims abstract description 32
- 230000001902 propagating effect Effects 0.000 claims abstract description 25
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 claims description 51
- 239000003153 chemical reaction reagent Substances 0.000 claims description 48
- 230000008569 process Effects 0.000 claims description 48
- 230000005855 radiation Effects 0.000 claims description 48
- 239000004411 aluminium Substances 0.000 claims description 42
- 230000002093 peripheral effect Effects 0.000 claims description 23
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 16
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 12
- 239000000463 material Substances 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 9
- 229910052799 carbon Inorganic materials 0.000 claims description 9
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 claims description 6
- 238000004519 manufacturing process Methods 0.000 abstract description 11
- 230000001590 oxidative effect Effects 0.000 abstract description 5
- 239000007789 gas Substances 0.000 description 68
- 239000010410 layer Substances 0.000 description 47
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 28
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 24
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 24
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 16
- JLTRXTDYQLMHGR-UHFFFAOYSA-N trimethylaluminium Chemical compound C[Al](C)C JLTRXTDYQLMHGR-UHFFFAOYSA-N 0.000 description 13
- 229910052786 argon Inorganic materials 0.000 description 12
- 125000004429 atom Chemical group 0.000 description 11
- 230000007935 neutral effect Effects 0.000 description 11
- 239000000843 powder Substances 0.000 description 11
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 9
- 229910052757 nitrogen Inorganic materials 0.000 description 8
- 125000004430 oxygen atom Chemical group O* 0.000 description 7
- 150000001875 compounds Chemical class 0.000 description 6
- 239000007800 oxidant agent Substances 0.000 description 6
- 230000003647 oxidation Effects 0.000 description 6
- 238000007254 oxidation reaction Methods 0.000 description 6
- 239000001307 helium Substances 0.000 description 5
- 229910052734 helium Inorganic materials 0.000 description 5
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 5
- 229910000077 silane Inorganic materials 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 229910052743 krypton Inorganic materials 0.000 description 4
- DNNSSWSSYDEUBZ-UHFFFAOYSA-N krypton atom Chemical compound [Kr] DNNSSWSSYDEUBZ-UHFFFAOYSA-N 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 229910052724 xenon Inorganic materials 0.000 description 4
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 238000001725 laser pyrolysis Methods 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- 238000004627 transmission electron microscopy Methods 0.000 description 3
- 241000252073 Anguilliformes Species 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical group [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000005430 electron energy loss spectroscopy Methods 0.000 description 2
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 2
- FFUAGWLWBBFQJT-UHFFFAOYSA-N hexamethyldisilazane Chemical compound C[Si](C)(C)N[Si](C)(C)C FFUAGWLWBBFQJT-UHFFFAOYSA-N 0.000 description 2
- 239000002086 nanomaterial Substances 0.000 description 2
- 239000012495 reaction gas Substances 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- SBIBMFFZSBJNJF-UHFFFAOYSA-N selenium;zinc Chemical compound [Se]=[Zn] SBIBMFFZSBJNJF-UHFFFAOYSA-N 0.000 description 2
- 238000011282 treatment Methods 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 239000000443 aerosol Substances 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 150000001335 aliphatic alkanes Chemical class 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000012295 chemical reaction liquid Substances 0.000 description 1
- 239000012792 core layer Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052752 metalloid Inorganic materials 0.000 description 1
- 150000002738 metalloids Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 125000002524 organometallic group Chemical group 0.000 description 1
- 229910052699 polonium Inorganic materials 0.000 description 1
- HZEBHPIOVYHPMT-UHFFFAOYSA-N polonium atom Chemical compound [Po] HZEBHPIOVYHPMT-UHFFFAOYSA-N 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229910052714 tellurium Inorganic materials 0.000 description 1
- PORWMNRCUJJQNO-UHFFFAOYSA-N tellurium atom Chemical compound [Te] PORWMNRCUJJQNO-UHFFFAOYSA-N 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
- C01B33/021—Preparation
- C01B33/027—Preparation by decomposition or reduction of gaseous or vaporised silicon compounds other than silica or silica-containing material
- C01B33/029—Preparation by decomposition or reduction of gaseous or vaporised silicon compounds other than silica or silica-containing material by decomposition of monosilane
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J12/00—Chemical processes in general for reacting gaseous media with gaseous media; Apparatus specially adapted therefor
- B01J12/005—Chemical processes in general for reacting gaseous media with gaseous media; Apparatus specially adapted therefor carried out at high temperatures, e.g. by pyrolysis
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
- B01J13/02—Making microcapsules or microballoons
- B01J13/04—Making microcapsules or microballoons by physical processes, e.g. drying, spraying
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
- B01J19/081—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing particle radiation or gamma-radiation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
- B01J19/12—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electromagnetic waves
- B01J19/121—Coherent waves, e.g. laser beams
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/24—Stationary reactors without moving elements inside
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J4/00—Feed or outlet devices; Feed or outlet control devices
- B01J4/001—Feed or outlet devices as such, e.g. feeding tubes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J4/00—Feed or outlet devices; Feed or outlet control devices
- B01J4/001—Feed or outlet devices as such, e.g. feeding tubes
- B01J4/002—Nozzle-type elements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J4/00—Feed or outlet devices; Feed or outlet control devices
- B01J4/001—Feed or outlet devices as such, e.g. feeding tubes
- B01J4/004—Sparger-type elements
-
- C01B31/36—
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/90—Carbides
- C01B32/914—Carbides of single elements
- C01B32/956—Silicon carbide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/90—Carbides
- C01B32/914—Carbides of single elements
- C01B32/956—Silicon carbide
- C01B32/963—Preparation from compounds containing silicon
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
- C01B33/021—Preparation
- C01B33/027—Preparation by decomposition or reduction of gaseous or vaporised silicon compounds other than silica or silica-containing material
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/28—Compounds of silicon
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/28—Compounds of silicon
- C09C1/30—Silicic acid
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/28—Compounds of silicon
- C09C1/30—Silicic acid
- C09C1/3045—Treatment with inorganic compounds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00049—Controlling or regulating processes
- B01J2219/00051—Controlling the temperature
- B01J2219/00139—Controlling the temperature using electromagnetic heating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
- B01J2219/0873—Materials to be treated
- B01J2219/0875—Gas
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/62—Submicrometer sized, i.e. from 0.1-1 micrometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
- C01P2004/82—Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases
- C01P2004/84—Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases one phase coated with the other
- C01P2004/86—Thin layer coatings, i.e. the coating thickness being less than 0.1 time the particle radius
Definitions
- the present invention relates to a process for producing multilayer particles (typically a core layer covered with an upper layer), typically by laser pyrolysis. It also relates to an associated device.
- Such a process enables a user for example to manufacture submicron particles of silicon or silicon carbide, each covered with a layer of aluminium or aluminium oxide.
- Processes for producing a material are known in which the raw material used is a mixture of two powders, at least one of which is characterized by an average grain size in the nanometric range:
- the whole is heated to a moderate temperature, optionally under pressure, without bringing it to the melting temperature (“sintering” process), in order to obtain a dense nanostructured material.
- the aim of the invention is to propose:
- the particles produced are preferably submicron particles, i.e. particles the diameter of which is less than 1000 nanometres, preferably comprised between 1 nanometre and 1000 nanometres.
- the submicron particles are nanometric particles, i.e. particles the diameter of which is less than 100 nanometres, preferably comprised between 1 nanometre and 100 nanometres.
- diameter of a particle is meant the distance between the two most distant points of this particle (for example the length in the case of a rod-shaped particle).
- core diameter of a particle is meant the distance between the two most distant points of this core.
- diameter of the layer comprising the second chemical element is meant the outside diameter, i.e. the distance between the two most distant points of this layer.
- Each reaction stream is preferably devoid of any agent that oxidizes the first chemical element, and the particle cores preferably comprise the first chemical element in the non-oxidized form.
- the particle cores preferably comprise the first chemical element in the non-oxidized form.
- Such a process according to the invention enables a user for example to manufacture submicron particles of non-oxidized silicon or of non-oxidized silicon carbide, each covered with a layer of pure or oxidized aluminium.
- the number of atoms of the second element introduced relative to the number of atoms of the first element introduced preferably corresponds to a ratio that is fixed by the thickness of the layer to be produced. This ratio is calculated from the molecular weights and densities of the materials:
- An additional parameter taking into account the aggregation of the particles may be introduced in the calculation of the molar ratio.
- the second chemical element may be introduced into the chamber in a gas stream surrounding each reaction stream.
- the second chemical element may be introduced into the chamber in a peripheral gas stream surrounding each reaction stream, emitted from several points distributed along a closed curve surrounding each reaction stream and propagating in the direction of each reaction stream.
- the second chemical element is preferably introduced into the chamber in the peripheral gas stream after the interaction zone of each reaction stream with the radiation beam.
- the process according to the invention may further comprise a step of introducing, into the reaction chamber, before the interaction zone of each reaction stream, a confining gas stream surrounding each reaction stream and propagating in the direction of flow.
- the second chemical element may be introduced into the chamber in the confining gas stream before the interaction zone of each reaction stream.
- the introduction of at least one reaction stream may comprise introducing at least one alignment of several reaction streams separated from one another by the confining gas stream and each comprising the first chemical element and each propagating in the direction of flow.
- the radiation beam can propagate in a direction of radiation preferably perpendicular to the direction of flow, and the streams of each alignment of reaction streams may be aligned in a direction of alignment perpendicular to the direction of flow and to the direction of radiation.
- the radiation beam can propagate in a direction of radiation preferably perpendicular to the direction of flow, and each reaction stream may have, in a plane perpendicular to the direction of flow, a section extending longitudinally in a direction of elongation perpendicular to the direction of flow and to the direction of radiation.
- the second chemical element may be introduced into the chamber with the first chemical element in each reaction stream before the interaction zone of each reaction stream.
- the first chemical element is preferably silicon (Si) and:
- the first chemical element is preferably introduced into the chamber in the form of silane (SiH 4 ).
- the second element is preferably aluminium. It is preferably introduced in the form of vaporized trimethylaluminium (Al(CH 3 ) 3 ), or generally in the form of a compound in the class of aluminium organometallics.
- particles are proposed, obtained by the process according to the invention.
- particles are proposed, each comprising:
- the particles are preferably submicron particles, i.e. particles the diameter (core+layer) of which is less than 1000 nanometres, preferably comprised between 1 nanometre and 1000 nanometres.
- the submicron particles are nanometric particles, i.e. particles the diameter (core+layer) of which is less than 100 nanometres, preferably comprised between 1 nanometre and 100 nanometres.
- a device for producing particles, comprising:
- the reagent is preferably devoid of any agent arranged for oxidizing the first chemical element.
- the injector of the second element and the injector of the first element are preferably arranged together in order to introduce a number of atoms of the second element relative to a number of atoms of the first element in a ratio allowing the desired thickness to be attained for producing the layer of aluminium or of aluminium oxide.
- the injector of the second chemical element may be arranged in order to introduce the second chemical element into the chamber in a gas stream surrounding each reaction stream.
- the injector of the second chemical element may be arranged in order to introduce the second chemical element into the chamber in a peripheral gas stream surrounding each reaction stream, emitted from several points distributed along a closed curve surrounding each reaction stream and arranged in order to direct the peripheral gas stream in the direction of each reaction stream.
- the injector of the second chemical element may be arranged in order to introduce the second chemical element into the chamber in the peripheral gas stream after the interaction zone of each reaction stream.
- the device according to the invention may further comprise an injector of confining gas arranged in order to introduce into the reaction chamber, before the interaction zone of each reaction stream, a confining gas stream surrounding each reaction stream and propagating in the direction of flow.
- the injector of the second chemical element may comprise the injector of confining gas.
- the injector of at least one reaction stream may be arranged in order to introduce, into the chamber, at least one alignment of several reaction streams separated from one another by the confining gas stream and each comprising the first chemical element and each propagating in the direction of flow.
- the emitter may be arranged so that the radiation beam propagates in a direction of radiation preferably perpendicular to the direction of flow, and the injector of at least one reaction stream may be arranged so that the streams of each alignment of reaction streams are aligned in a direction of alignment perpendicular to the direction of flow and to the direction of radiation.
- the emitter may be arranged so that the radiation beam propagates in a direction of radiation preferably perpendicular to the direction of flow, and the injector of at least one reaction stream may be arranged so that each reaction stream has, in a plane perpendicular to the direction of flow, a section extending longitudinally in a direction of elongation perpendicular to the direction of flow and to the direction of radiation.
- the injector of the second chemical element may be arranged in order to introduce the second element into the chamber with the first chemical element in each reaction stream before the interaction zone of each reaction stream.
- the first chemical element is preferably silicon (Si) and:
- the second element is preferably aluminium.
- FIG. 1 is a diagrammatic cross-section profile view of a reaction stream (this may equally well be stream 1 , 100 , 101 , 102 , 103 , 104 , 105 or 106 depending on the variant considered) in a device according to the invention,
- FIG. 2 is a diagrammatic cross-section profile view (this may equally well be at the level of stream 1 , 101 , 102 , or 103 depending on the variant considered) of a device according to the invention,
- FIG. 3 is a diagrammatic cross-section front view of an alignment of reaction streams 101 , 102 , 103 in a device according to the invention
- FIG. 4 is a diagrammatic cross-section profile view (this may equally well be at the level of steams 1 , 100 or 101 , 104 or 102 , 105 or 103 , 106 depending on the variant considered) of a variant of a device according to the invention,
- FIG. 5 is a perspective view of a reaction stream 1 accompanied by another optional reaction stream 100 ,
- FIG. 6 is a perspective view of a first alignment of reaction streams 101 , 102 , 103 accompanied by another optional alignment of reaction streams 104 , 105 , 106 ,
- FIG. 7 is a diagrammatic cross-section profile view of a reaction stream (this may equally well be stream 1 , 100 , 101 , 102 , 103 , 104 , 105 or 106 depending on the variant considered) and of an annular injector 22 arranged for diffusing a peripheral gas stream 7 ,
- FIG. 8 is a diagrammatic perspective view of a reaction stream (this may equally well be stream 1 , 100 , 101 , 102 , 103 , 104 , 105 or 106 depending on the variant considered) and of the annular injector 22 ,
- FIG. 9 is a diagrammatic cross-section profile view of a particle manufactured according to the invention.
- FIG. 10 is a diagrammatic cross-section profile view of another particle manufactured according to the invention.
- FIG. 11 is a graph of detection of chemical elements by techniques of transmission electron microscopy and of loss of electron energy (STEM/HAADS/EELS), as a function of the position along a segment starting from a core of a particle and reaching the layer 16 of this same particle and then the exterior of this particle.
- STEM/HAADS/EELS loss of electron energy
- variants of the invention can be considered comprising only a selection of the characteristics described hereinafter, in isolation from the other characteristics described (even if this selection is isolated within a phrase containing other characteristics), if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention with respect to the state of the art.
- This selection comprises at least one, preferably functional, characteristic without structural details, or with only a part of the structural details if this part alone is sufficient to confer a technical advantage or to differentiate the invention with respect to the state of the prior art.
- FIGS. 1 to 6 A first embodiment of the device 9 according to the invention will be described first, referring to FIGS. 1 to 6 .
- This first embodiment of the device 9 for producing particles 10 by laser pyrolysis comprises a reagent source 4 .
- the reagent preferably comprises at least one reaction gas and/or at least one reaction liquid in the form of aerosol.
- the reagent comprises a first chemical element.
- the first chemical element is preferably a metal (preferably from iron, aluminium, titanium) or a metalloid (from boron, silicon, germanium, arsenic, antimony, tellurium, polonium). More precisely, the first chemical element in the reagent is preferably silicon, preferably in the form of SiH 4 .
- the reagent is preferably reaction gas (typically SiH 4 gas, or SiH 4 +C 2 H 2 or SiH 4 +C 2 H 4 or SiH 4 +CH 4 gas).
- the device 9 further comprises a reaction chamber 8 (preferably delimited by stainless steel walls) connected to the reagent source 4 .
- the reaction chamber 8 is filled with a neutral gas atmosphere (from helium, argon, krypton, xenon, nitrogen or a mixture), preferably argon or nitrogen.
- a neutral gas atmosphere from helium, argon, krypton, xenon, nitrogen or a mixture, preferably argon or nitrogen.
- a reagent injector 5 is arranged in order to introduce, into the chamber 8 and originating from the reagent source 4 , at least one reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , each reaction stream propagating in an identical direction of flow 11 for all the reaction streams and in one reaction stream zone 6 per reaction stream.
- An emitter 19 (typically a laser source) of a radiation beam 3 (typically a laser beam, preferably having an area between 30 mm 2 and 3000 mm 2 in cross-section perpendicular to the direction 12 , width in direction 13 , 18 preferably comprised between 2 and 5 cm, wavelength between 9 microns and 11 microns, preferably 10.6 microns for SiH 4 and power comprised between 50 and 5000 W and frequency comprised between 10000 and 100000 Hz) is arranged in order to project the radiation beam 3 through the reaction chamber 8 so that this beam 3 intersects, in one interaction zone 14 per reaction stream zone 6 , with each reaction stream zone 6 so that particle cores 15 comprising the first chemical element are formed in each reaction stream.
- a radiation beam 3 typically a laser beam, preferably having an area between 30 mm 2 and 3000 mm 2 in cross-section perpendicular to the direction 12 , width in direction 13 , 18 preferably comprised between 2 and 5 cm, wavelength between 9 microns and 11 microns, preferably
- each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 or reaction stream zone 6 consists of three parts:
- the beam 3 is shaped by an optical system to give it a cross-section that is preferably rectangular (but could also be elliptical) and preferably focused vertically (i.e. the area of which decreases with the advance of the beam 3 in the direction of radiation 12 ), as described in documents FR 2 894 493 and FR 2 877 591.
- the beam 3 enters the chamber 8 through a window 23 of ZnSe and leaves the chamber 8 through another window 24 of ZnSe before being stopped by a non-reflective calorimeter 25 (“beam stopper”).
- the device 9 further comprises a source of a second chemical element.
- the second chemical element is preferably aluminium injected in the form of trimethylaluminium (or TMA, of chemical formula Al(CH 3 ) 3 , or generally in the form of a compound in the class of aluminium organometallics) heated and vaporized preferably in a neutral gas, such as for example argon.
- An injector of a second element is arranged in order to introduce, into the reaction chamber 8 , the second chemical element from the source of second element so that this second chemical element is able to interact in the chamber 8 with each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 in order to cover the particle cores 15 with a layer 16 comprising the second chemical element.
- the reagent in the source 4 and injected into chamber 8 is devoid of oxidizing agent arranged for oxidizing the first chemical element.
- agent arranged for oxidizing the first chemical element also called “oxidizing agent of the first chemical element”
- any atom or molecule for example N 2 O
- the reagent for example SiH 4 gas, optionally mixed with C 2 H 2 or C 2 H 4 or CH 4
- the reagent in the source 4 and injected into the chamber 8 is devoid of oxygen atoms.
- the injector ( 5 , 21 and/or 22 ) of the second element and the injector 5 of the first element are arranged together within the device 9 (by their flow rate and their proportions of the various gases, optionally mixed, that they deliver, such as SiH 4 for the injector 5 , argon or nitrogen for the injector 21 and C 2 H 2 , C 2 H 4 , CH 4 for the injector 5 and/or 21 and/or 22 ) in order to introduce into the reaction chamber 8 per unit of time (typically per minute) a number of atoms of the second element relative to a number of atoms of the first element according to a ratio selected for reaching the desired thickness of the layer 16 .
- the injector ( 5 , 21 and/or 22 ) of the second element and the injector 5 of the first element are arranged together within the device 9 in order to introduce the desired molar ratio between the second and the first element.
- n 2 n 1 M 1 d 1 ⁇ V 1 ⁇ d 2 ⁇ V 2 M 2
- n 1 is the number of atoms constituting the particle core 15 , introduced into the reaction chamber (preferably only in at least one reaction stream) per unit of time. For example:
- d 1 is the density of the material (for example pure silicon, or pure silicon carbide) constituting the core 15 of the particles,
- M 1 is the molecular weight of the material (for example pure silicon or silicon carbide) making up the core 15 of the particles,
- V 1 is the desired volume for a particle core 15 of diameter D 1 , approximately equal to
- n 2 is the number of atoms constituting the layer 16 , introduced (in the sum of the reaction streams 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , the confining stream 2 and optionally peripheral streams 7 if they are present) into the reaction chamber per unit of time.
- the reaction streams 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 the confining stream 2 and optionally peripheral streams 7 if they are present
- d 2 is the density of the material (for example pure aluminium or oxidized aluminium) constituting the layer 16 ,
- M 2 is the molecular weight of the material (for example pure aluminium or oxidized aluminium) constituting the layer 16 ,
- V 2 is the desired volume for a layer 16 , approximately equal to
- the device 9 further comprises a source 20 of confining gas comprising confining gas and an injector 21 of confining gas arranged in order to introduce into the reaction chamber 8 , before (relative to the direction of flow 11 ) the interaction zone 14 of each reaction stream, a confining gas stream 2 (preferably common to all the reaction streams) surrounding each reaction stream 1 , 100 101 , 102 , 103 , 104 , 105 , 106 (more precisely in contact with each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 on the whole perimeter of each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 at least starting from the injection of the reagent into the chamber 8 up to the interaction zone 14 of each reaction stream, this perimeter being defined according to a closed line contained in a plane perpendicular to the direction of flow 11 ) and propagating in the direction of flow 11 .
- the confining gas comprises a neutral gas (from helium, argon, nitrogen or a mixture thereof, preferably argon or nitrogen).
- the confining gas stream 2 has two functions:
- the emitter 19 is arranged so that the radiation beam 3 propagates in a direction of radiation 12 perpendicular to the direction of flow 11 .
- the injector 5 of at least one reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 is arranged so that each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 has, in a plane perpendicular to the direction of flow 11 , a section that may extend longitudinally in a direction of elongation 13 perpendicular to the direction of flow 11 and to the direction of radiation 12 .
- the reagent injector 5 is arranged in order to introduce into the chamber 8 , and originating from the reagent source 4 , a single reaction stream 1 that propagates in the direction of flow 11 in a reaction stream zone 6 .
- the cross-section of the injector 5 is typically an oval with a depth of 4 mm in the direction 12 and a width of 2 cm in the direction 13 .
- the injector 5 of at least one reaction stream is arranged in order to introduce, into the chamber 8 and originating from the reagent source 4 , an alignment of several reaction streams 101 , 102 , 103 separated from one another by the confining gas stream 2 and each comprising the first chemical element and each propagating in the direction of flow 11 .
- Each stream 101 , 102 or 103 propagates in the direction of flow 11 in its own reaction stream zone 6 .
- the injector 5 of at least one reaction stream 101 , 102 , 103 is arranged so that, within the alignment of streams 101 , 102 , 103 , the various reaction streams 101 , 102 , 103 are aligned in a direction of alignment 18 perpendicular to the direction of flow 11 and to the direction of radiation 12 .
- the injector 5 is subdivided into several injection nozzles 201 , 202 , 203 (one nozzle per reaction stream).
- Each nozzle has a section that is typically a disk, an oval or an oblong with depth of 3 mm in the direction 12 and with width of 4 mm in the direction 13 , 18 .
- the number of reaction streams 101 , 102 , 103 and of nozzles 201 , 202 , 203 is by no means limited to three; there could be many more of them, this number depending on the width of the laser spot, which can range from 2 to 5 cm or even more.
- the injector 5 of at least one reaction stream is arranged in order to introduce, into the chamber 8 , several reaction streams 1 , 100 , separated from one another by the confining gas stream 2 and each comprising the first chemical element and each propagating in the direction of flow 11 .
- the reagent injector 5 is arranged in order to introduce, into the chamber 8 and originating from the reagent source 4 , several reaction streams 1 , 100 , each stream 1 , 100 propagating in the direction of flow 11 in its own reaction stream zone 6 . These streams 1 , 100 are spaced apart in the direction of radiation 12 .
- the losses of the beam 3 by absorption by the reaction stream 1 are compensated by the focusing (or “convergence”) of the beam 3 so that the incident power density of the beam 3 on each stream 1 or 100 is identical for all the streams 1 , 100 as described in document FR 2 877 591.
- This variant makes it possible to increase the rate of production on a single reactor with optimum consumption of laser energy for production.
- the injector 5 of at least one reaction stream is arranged in order to introduce, into the chamber 8 and originating from the reagent source 4 , several alignments of reaction streams separated from one another by the confining gas stream 2 and each comprising the first chemical element and each propagating in the direction of flow 11 .
- FIG. 6 shows a first alignment of streams 101 , 102 , 103 and a second alignment of streams 104 , 105 , 106 .
- Each stream 101 , 102 , 103 , 104 , 105 or 106 propagates in the direction of flow 11 in its own reaction stream zone 6 .
- the injector 5 of at least one reaction stream is arranged so that the streams 101 , 102 , 103 or 104 , 104 and 105 respectively (or more precisely their cross-section in a plane perpendicular to the direction of flow 11 ) within each alignment are aligned in a direction of alignment 18 perpendicular to the direction of flow 11 and to the direction of radiation 12 .
- the alignments of streams are spaced apart in the direction of radiation 12 .
- the various alignments of streams are parallel to one another in the same direction 18 .
- the injector 5 is subdivided into several injection nozzles (one nozzle per reaction stream). Each nozzle has a cross-section that is typically an oval with a depth of 3 mm in the direction 12 and with a width of 4 mm in the direction 13 , 18 .
- the losses of beam 3 by absorption by the first alignment of streams 101 , 102 , 103 are compensated by the focusing (or “convergence”) of the beam 3 so that the incident power density of the beam 3 on each alignment of streams 101 , 102 , 103 or 104 , 105 , 106 is identical for all the streams 101 , 102 , 103 , 104 , 105 or 106 according to the principle described in document FR 2 877 591.
- the injector of the second chemical element is arranged in order to introduce the second element into the chamber 8 with the first chemical element in each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 before (relative to the direction of flow 11 ) the interaction zone 14 of each reaction stream.
- the injector of the second chemical element comprises the reagent injector 5 . More precisely, the injector of the second chemical element and the reagent injector 5 are combined.
- a second embodiment of the device 9 according to the invention is strictly identical to the first embodiment of the device 9 described above (whatever variant is considered from its four variants described above), apart from the fact that the injector of the second chemical element is arranged in order to introduce the second chemical element into the chamber 8 in a gas stream 2 surrounding each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 .
- the injector of the second chemical element is arranged in order to introduce the second chemical element into the chamber 8 in the confining gas stream 2 before (relative to the direction of flow 11 ) the interaction zone 14 of each reaction stream.
- the injector of the second chemical element comprises the injector 21 of confining gas. More precisely, the injector of the second chemical element and the injector 21 of confining gas are combined.
- This second embodiment is preferably implemented within the second or fourth variant (comprising one or more alignment(s) of streams 101 , 102 , 103 and 104 , 105 , 106 in FIGS. 3 and 6 ) as this makes it possible to maximize the area of interaction between the confining gas 2 comprising the second chemical element and each reaction stream comprising the first chemical element.
- a third embodiment of the device 9 according to the invention is strictly identical to the first embodiment of the device 9 described above (whatever variant is considered from its four variants described above), apart from the fact that the injector of the second chemical element is arranged in order to introduce the second chemical element into the chamber 8 in a gas stream 7 surrounding each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 .
- the injector of the second chemical element comprises an injector 22 (preferably of annular shape):
- the injector of the second chemical element is arranged in order to introduce the second chemical element into the chamber 8 in a peripheral gas stream 7 surrounding this reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , or 106 and emitted from several points 17 distributed along a closed curve (typically annular shape of injector 22 ) surrounding this reaction stream and arranged in order to direct the peripheral gas stream 7 in the direction of this reaction stream.
- a closed curve typically annular shape of injector 22
- the injector of the second chemical element is arranged in order to introduce the second chemical element into the chamber 8 in the peripheral gas stream 7 after (relative to the direction of flow 11 ) the interaction zone 14 of this reaction stream.
- This is particularly beneficial, as it makes it possible to have good control (by adjusting the power of the beam 3 ) and good uniformity of manufacture of the cores 15 of the particles 10 .
- Manufacture of the layers 16 on the cores 15 of the particles will not take energy directly from the beam 3 and therefore does not disturb the control of the manufacture of the cores 15 .
- manufacture of the layers 16 on the particle cores 15 utilizes the energy of the flame 26 after the interaction zone 14 .
- This third embodiment of the device 9 comprises means for moving (not shown, comprising for example a micro-displacement stage) each injector 22 in the direction of flow 11 so as to optimize the layer 16 manufactured for the particles 10 .
- the injector of the second chemical element may therefore comprise:
- This process according to the invention for producing particles 10 by laser pyrolysis comprises the following steps:
- the reagent of the reaction stream is devoid of agent that oxidizes the first chemical element.
- the particle cores 15 obtained by the process according to the invention comprise the first chemical element in the non-oxidized form.
- the number of atoms introduced per unit of time is in a molar ratio allowing the desired thickness to be attained for producing a layer 16 of aluminium or of aluminium oxide obtained by oxidation of the layer of aluminium.
- the radiation beam 3 propagates in the direction of radiation 12 perpendicular to the direction of flow 11 .
- Each reaction stream has, in a plane perpendicular to the direction of flow 11 , a section extending longitudinally in the direction of elongation 13 perpendicular to the direction of flow 11 and to the direction of radiation 12 .
- the particles 10 thus manufactured drop into a recovery device 27 where they are cooled before being conveyed by gravity and/or vacuum to a plant that uses the particles or to a container for storage.
- the second chemical element is introduced into the chamber 8 with the first chemical element in the reagent in each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 before (relative to the direction of flow 11 ) the interaction zone 14 of each reaction stream.
- the second chemical element is introduced into the chamber 8 in a gas stream 2 or 7 surrounding each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 and in contact with each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 .
- the second chemical element is introduced into the chamber 8 in the confining gas stream 2 before (relative to the direction of flow 11 ) the interaction zone 14 of each reaction stream.
- the introduction of at least one reaction stream comprises an introduction of several aligned reaction streams (alignment 101 , 102 , 103 and optionally in addition alignment 104 , 105 , 106 ) separated from one another by the confining gas stream 2 and each comprising the first chemical element and each propagating in the direction of flow 11 .
- the confining gas stream 2 is preferably common to all the reaction streams and there is no discontinuity between the various reaction streams.
- the radiation beam 3 propagates in the direction of radiation 12 perpendicular to the direction of flow 11 , and the various reaction streams 101 , 102 , 103 or 104 , 105 , 106 within an alignment are aligned in the direction of alignment 18 perpendicular to the direction of flow 11 and to the direction of radiation 12 .
- the second chemical element is introduced into the chamber 8 in a peripheral gas stream 7 surrounding each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , emitted from several points 17 distributed along a closed curve surrounding each reaction stream and propagating in the direction of the reaction stream.
- the second chemical element is introduced into the chamber 8 in the peripheral gas stream 7 after (relative to the direction of flow 11 ) the interaction zone 14 of each reaction stream.
- the first chemical element is silicon
- the second chemical element is pure aluminium, which may be oxidized after production.
- the laser used is a CO 2 laser, the surface density of incident energy is 800 W per square centimetre.
- the first chemical element is introduced at ambient temperature (approximately 20° C.) into the chamber 8 in the form of gaseous SiH 4 , at approximately 18 litres per minute of gaseous SiH 4 .
- the reagent of each reaction stream is thus gaseous silane (SiH 4 ) that is not mixed with oxidizing agents or with oxygen atoms or with molecules comprising oxygen atoms, so that the particle cores 15 comprise (and even preferably consist of), preferably non-oxidized, silicon (Si).
- the confining gas 2 comprises a neutral gas (gaseous argon) introduced into the chamber 8 at ambient temperature at 50 litres per minute.
- the second chemical element is introduced into the reaction chamber in the form of trimethylaluminium (or TMA, of chemical formula Al(CH 3 ) 3 ) or generally in the form of a compound in the class of aluminium organometallics. It is introduced into the chamber at a temperature of 50° C. in the peripheral gas stream 7 , which also carries neutral argon gas.
- the total gas flow rate Argon+TMA is 33 litres per minute gaseous.
- the number of aluminium atoms introduced (which plays the role of the second element here) relative to the number of atoms of the first element (silicon) introduced is a ratio of one aluminium atom to 3.7 silicon atoms (1 mole of Al(CH 3 ) 3 to 3.7 moles of SiH 4 ).
- the layer 16 of each particle thus obtained is of non-oxidized aluminium.
- the particles 10 are optionally:
- the particles obtained may then be used, by various processes including:
- Example 2 will only be described where it differs from example 1.
- Example 2 is identical to example 1, except that in example 2 the surface density of incident energy is 1500 W per square centimetre and the reagent in each reaction stream is a mixture of:
- Particles according to the first example were manufactured according to example 1 and example 2 with the third embodiment of device 9 alone (i.e. with the third embodiment of the process according to the invention). They are subjected to slow oxidation at the end of production so as to generate a layer of aluminium oxide.
- the size of the particles 10 obtained corresponds to an average core diameter D 1 determined from measurement of the specific surface and density:
- the homogeneity of the layer 16 is excellent (for example by comparison between FIGS. 9 and 10 ) using the third embodiment of the process according to the invention, in which the second chemical element is introduced into the chamber 8 in a gas stream 7 surrounding each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 and in contact with each reaction stream 1 , 100 , 101 , 102 , 103 , 104 , 105 , 106 .
- FIG. 10 for each particle 10 a layer 16 of almost uniform thickness is obtained, which covers the whole of its core 15 .
- the particles are almost spherical, and are pronounced of faceted balls.
- FIG. 11 is a graph of detection of chemical elements by STEM/EELS techniques of transmission electron microscopy, as a function (on the x-axis) of the position along a segment starting from a core 15 of a particle and continuing over the layer 16 of this same particle and then to the exterior of this particle.
- the y-axis shows intensity related to the proportion of the elements detected.
- the layer 16 aluminium and oxygen are detected, but not carbon or silicon.
- the imaged zone of core 15 is superimposed on the layer 16 .
- it is a profile obtained by moving an analysis probe along an axis situated above the particle, and when the probe moves over the core 15 this leads to superposition of the majority signals from the core and the minority signals from the surface.
- the layer 16 does not comprise the first chemical element (in any form).
- the core 15 does not comprise the first chemical element in the oxidized form, but comprises this first chemical element only in the non-oxidized form.
Abstract
Description
- The present invention relates to a process for producing multilayer particles (typically a core layer covered with an upper layer), typically by laser pyrolysis. It also relates to an associated device.
- Such a process enables a user for example to manufacture submicron particles of silicon or silicon carbide, each covered with a layer of aluminium or aluminium oxide.
- Processes for producing a material are known in which the raw material used is a mixture of two powders, at least one of which is characterized by an average grain size in the nanometric range:
-
- a powder of particles of a first type, for example of silicon carbide, and
- a powder of particles of a second type, which are particles of aluminium or aluminium oxide.
- Then the whole is heated to a moderate temperature, optionally under pressure, without bringing it to the melting temperature (“sintering” process), in order to obtain a dense nanostructured material.
- There may be problems of inhomogeneity between the silicon carbide and the aluminium oxide or the aluminium in the material obtained, in particular arising from difficulties in mixing two powders, at least one of which is a nanometric powder. These difficulties arise from the agglomeration forces, which are greater in the case of nanometric powders, and which make it difficult to obtain a material of homogeneous microstructure or nanostructure when a powder of nanometric size is used.
- Moreover, there may be problems of binding or of chemical compatibility between the particles of the two powders, making it necessary to carry out chemical or thermal post-treatments on the powders before using them.
- The aim of the invention is to propose:
-
- a novel raw material,
- a process for producing this raw material,
- various uses of this raw material.
- This aim is achieved with a process for producing particles, comprising the following steps:
-
- Introducing, into a reaction chamber, at least one reaction stream comprising a first chemical element (typically silicon), propagating in one direction of flow,
- Projecting a radiation beam through the reaction chamber, intersecting with each reaction stream in one interaction zone per reaction stream, in order to form, in each reaction stream, particle cores comprising the first chemical element, and
- Introducing, into the reaction chamber, a second chemical element (typically aluminium), interacting with each reaction stream in order to cover the particle cores with a layer comprising the second chemical element.
- The particles produced are preferably submicron particles, i.e. particles the diameter of which is less than 1000 nanometres, preferably comprised between 1 nanometre and 1000 nanometres. Preferably, the submicron particles are nanometric particles, i.e. particles the diameter of which is less than 100 nanometres, preferably comprised between 1 nanometre and 100 nanometres. By “diameter of a particle” is meant the distance between the two most distant points of this particle (for example the length in the case of a rod-shaped particle). Similarly, by “core diameter” of a particle is meant the distance between the two most distant points of this core. Similarly, by “diameter of the layer comprising the second chemical element” is meant the outside diameter, i.e. the distance between the two most distant points of this layer.
- Each reaction stream is preferably devoid of any agent that oxidizes the first chemical element, and the particle cores preferably comprise the first chemical element in the non-oxidized form. Thus, by dispensing with an oxidizing agent that is capable of oxidizing the first chemical element, particles may be obtained the core of which comprises the non-oxidized first element. The layer of second element protects the core against oxidation, and makes it possible to keep the first element in a non-oxidized state, which leaves more choice for the possible uses of the particles produced at lower cost. This makes it possible to keep the first element of the core non-oxidized for novel uses of non-oxidized particles without the need to apply a treatment that aims to reduce the oxygen content.
- Thus, such a process according to the invention enables a user for example to manufacture submicron particles of non-oxidized silicon or of non-oxidized silicon carbide, each covered with a layer of pure or oxidized aluminium.
- The number of atoms of the second element introduced relative to the number of atoms of the first element introduced preferably corresponds to a ratio that is fixed by the thickness of the layer to be produced. This ratio is calculated from the molecular weights and densities of the materials:
-
- pure aluminium or aluminium oxide for the layer depending on the use, and
- for the core, silicon if the reaction stream for producing the particle core only contains the element silicon, or silicon carbide if the reaction stream contains, in addition to the element silicon, the element carbon in a ratio close to 1 to 1 (1 molecule for the element silicon and 1 molecule for the element carbon).
- An additional parameter taking into account the aggregation of the particles may be introduced in the calculation of the molar ratio.
- The second chemical element may be introduced into the chamber in a gas stream surrounding each reaction stream.
- The second chemical element may be introduced into the chamber in a peripheral gas stream surrounding each reaction stream, emitted from several points distributed along a closed curve surrounding each reaction stream and propagating in the direction of each reaction stream. The second chemical element is preferably introduced into the chamber in the peripheral gas stream after the interaction zone of each reaction stream with the radiation beam. These arrangements make it possible to maintain complete flexibility of the process, allowing the particle cores to be produced, and in particular full capacity for producing cores of adjustable size. These embodiments significantly improve control of the homogeneity of distribution and thickness of the layer of second element on each particle core.
- The process according to the invention may further comprise a step of introducing, into the reaction chamber, before the interaction zone of each reaction stream, a confining gas stream surrounding each reaction stream and propagating in the direction of flow. The second chemical element may be introduced into the chamber in the confining gas stream before the interaction zone of each reaction stream.
- The introduction of at least one reaction stream may comprise introducing at least one alignment of several reaction streams separated from one another by the confining gas stream and each comprising the first chemical element and each propagating in the direction of flow.
- The radiation beam can propagate in a direction of radiation preferably perpendicular to the direction of flow, and the streams of each alignment of reaction streams may be aligned in a direction of alignment perpendicular to the direction of flow and to the direction of radiation.
- The radiation beam can propagate in a direction of radiation preferably perpendicular to the direction of flow, and each reaction stream may have, in a plane perpendicular to the direction of flow, a section extending longitudinally in a direction of elongation perpendicular to the direction of flow and to the direction of radiation.
- The second chemical element may be introduced into the chamber with the first chemical element in each reaction stream before the interaction zone of each reaction stream.
- The first chemical element is preferably silicon (Si) and:
-
- the particle cores may be of non-oxidized silicon; or
- carbon (preferably in the form of acetylene (C2H2) or C2H4 or CH4) may be introduced into the chamber with the first chemical element in each reaction stream before the interaction zone of each reaction stream, so that the particle cores comprise (or preferably consist of) silicon carbide (SiC), preferably non-oxidized.
- The first chemical element is preferably introduced into the chamber in the form of silane (SiH4).
- The second element is preferably aluminium. It is preferably introduced in the form of vaporized trimethylaluminium (Al(CH3)3), or generally in the form of a compound in the class of aluminium organometallics.
- According to yet another aspect of the invention, particles are proposed, obtained by the process according to the invention.
- According to yet another aspect of the invention, particles are proposed, each comprising:
-
- a core comprising a first chemical element (preferably silicon) that is not oxidized (typically in the form of silicon (Si) or preferably silicon carbide (SiC)), having a diameter comprised between 3 and 900 nm, preferably comprised between 3 and 99 nm (preferably with a standard deviation between 1 and 90 nm), and
- a layer surrounding the core, comprising (preferably consisting only of) a second chemical element (preferably aluminium) and having a layer thickness (not necessarily homogeneous) of at least 0.5 nm, preferably between 0.5 and 50 nm.
- The particles are preferably submicron particles, i.e. particles the diameter (core+layer) of which is less than 1000 nanometres, preferably comprised between 1 nanometre and 1000 nanometres. Preferably, the submicron particles are nanometric particles, i.e. particles the diameter (core+layer) of which is less than 100 nanometres, preferably comprised between 1 nanometre and 100 nanometres.
- According to yet another aspect of the invention, uses of particles according to the invention are proposed, including:
-
- a process, characterized in that a component is manufactured by sintering a powder comprising (preferably consisting of) particles according to the invention, and/or
- a process, in which aluminium particles are mixed with particles according to the invention, then the mixture is heated and then cooled so as to bond the aluminium particles with the particles according to the invention.
- According to yet another aspect of the invention, a device is proposed for producing particles, comprising:
-
- a reagent source comprising reagent, this reagent comprising a first chemical element;
- a reaction chamber connected to the reagent source;
- a reagent injector arranged in order to introduce, into the chamber, and originating from the reagent source, at least one reaction stream comprising said reagent, propagating in a direction of flow in one reaction stream zone per reaction stream,
- an emitter of a radiation beam arranged in order to project the radiation beam through the reaction chamber, intersecting with each reaction stream zone in one interaction zone per reaction stream,
- a source of a second chemical element, and
- an injector of the second element arranged in order to introduce, into the reaction chamber, the second chemical element from the source of the second element in such a way that this second chemical element is able to interact in the chamber with each reaction stream.
- The reagent is preferably devoid of any agent arranged for oxidizing the first chemical element.
- The injector of the second element and the injector of the first element are preferably arranged together in order to introduce a number of atoms of the second element relative to a number of atoms of the first element in a ratio allowing the desired thickness to be attained for producing the layer of aluminium or of aluminium oxide.
- The injector of the second chemical element may be arranged in order to introduce the second chemical element into the chamber in a gas stream surrounding each reaction stream.
- The injector of the second chemical element may be arranged in order to introduce the second chemical element into the chamber in a peripheral gas stream surrounding each reaction stream, emitted from several points distributed along a closed curve surrounding each reaction stream and arranged in order to direct the peripheral gas stream in the direction of each reaction stream. The injector of the second chemical element may be arranged in order to introduce the second chemical element into the chamber in the peripheral gas stream after the interaction zone of each reaction stream.
- The device according to the invention may further comprise an injector of confining gas arranged in order to introduce into the reaction chamber, before the interaction zone of each reaction stream, a confining gas stream surrounding each reaction stream and propagating in the direction of flow. The injector of the second chemical element may comprise the injector of confining gas.
- The injector of at least one reaction stream may be arranged in order to introduce, into the chamber, at least one alignment of several reaction streams separated from one another by the confining gas stream and each comprising the first chemical element and each propagating in the direction of flow.
- The emitter may be arranged so that the radiation beam propagates in a direction of radiation preferably perpendicular to the direction of flow, and the injector of at least one reaction stream may be arranged so that the streams of each alignment of reaction streams are aligned in a direction of alignment perpendicular to the direction of flow and to the direction of radiation.
- The emitter may be arranged so that the radiation beam propagates in a direction of radiation preferably perpendicular to the direction of flow, and the injector of at least one reaction stream may be arranged so that each reaction stream has, in a plane perpendicular to the direction of flow, a section extending longitudinally in a direction of elongation perpendicular to the direction of flow and to the direction of radiation.
- The injector of the second chemical element may be arranged in order to introduce the second element into the chamber with the first chemical element in each reaction stream before the interaction zone of each reaction stream.
- The first chemical element is preferably silicon (Si) and:
-
- the reagent may comprise silane (SiH4), and/or
- the reagent may comprise carbon (preferably in the form of acetylene (C2H2) or C2H4 or CH4).
- The second element is preferably aluminium.
- Other advantages and characteristics of the invention will become apparent on examination of the detailed description of an embodiment which is in no way limitative, and the attached diagrams, in which:
-
FIG. 1 is a diagrammatic cross-section profile view of a reaction stream (this may equally well bestream -
FIG. 2 is a diagrammatic cross-section profile view (this may equally well be at the level ofstream -
FIG. 3 is a diagrammatic cross-section front view of an alignment of reaction streams 101, 102, 103 in a device according to the invention, -
FIG. 4 is a diagrammatic cross-section profile view (this may equally well be at the level ofsteams -
FIG. 5 is a perspective view of areaction stream 1 accompanied by anotheroptional reaction stream 100, -
FIG. 6 is a perspective view of a first alignment of reaction streams 101, 102, 103 accompanied by another optional alignment of reaction streams 104, 105, 106, -
FIG. 7 is a diagrammatic cross-section profile view of a reaction stream (this may equally well bestream annular injector 22 arranged for diffusing aperipheral gas stream 7, -
FIG. 8 is a diagrammatic perspective view of a reaction stream (this may equally well bestream annular injector 22, -
FIG. 9 is a diagrammatic cross-section profile view of a particle manufactured according to the invention, -
FIG. 10 is a diagrammatic cross-section profile view of another particle manufactured according to the invention, and -
FIG. 11 is a graph of detection of chemical elements by techniques of transmission electron microscopy and of loss of electron energy (STEM/HAADS/EELS), as a function of the position along a segment starting from a core of a particle and reaching thelayer 16 of this same particle and then the exterior of this particle. - As these embodiments are in no way limitative, variants of the invention can be considered comprising only a selection of the characteristics described hereinafter, in isolation from the other characteristics described (even if this selection is isolated within a phrase containing other characteristics), if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention with respect to the state of the art. This selection comprises at least one, preferably functional, characteristic without structural details, or with only a part of the structural details if this part alone is sufficient to confer a technical advantage or to differentiate the invention with respect to the state of the prior art.
- A first embodiment of the
device 9 according to the invention will be described first, referring toFIGS. 1 to 6 . - This first embodiment of the
device 9 for producingparticles 10 by laser pyrolysis comprises areagent source 4. The reagent preferably comprises at least one reaction gas and/or at least one reaction liquid in the form of aerosol. The reagent comprises a first chemical element. The first chemical element is preferably a metal (preferably from iron, aluminium, titanium) or a metalloid (from boron, silicon, germanium, arsenic, antimony, tellurium, polonium). More precisely, the first chemical element in the reagent is preferably silicon, preferably in the form of SiH4. The reagent is preferably reaction gas (typically SiH4 gas, or SiH4+C2H2 or SiH4+C2H4 or SiH4+CH4 gas). - The
device 9 further comprises a reaction chamber 8 (preferably delimited by stainless steel walls) connected to thereagent source 4. - The
reaction chamber 8 is filled with a neutral gas atmosphere (from helium, argon, krypton, xenon, nitrogen or a mixture), preferably argon or nitrogen. - A
reagent injector 5 is arranged in order to introduce, into thechamber 8 and originating from thereagent source 4, at least onereaction stream flow 11 for all the reaction streams and in onereaction stream zone 6 per reaction stream. - An emitter 19 (typically a laser source) of a radiation beam 3 (typically a laser beam, preferably having an area between 30 mm2 and 3000 mm2 in cross-section perpendicular to the
direction 12, width indirection radiation beam 3 through thereaction chamber 8 so that thisbeam 3 intersects, in one interaction zone 14 perreaction stream zone 6, with eachreaction stream zone 6 so thatparticle cores 15 comprising the first chemical element are formed in each reaction stream. - Thus, each
reaction stream reaction stream zone 6 consists of three parts: -
- an interaction zone 14 with the
beam 3, - a part situated before (relative to the direction of flow 11) its interaction zone 14 and comprising the reagent as introduced into the
chamber 8, and - a part situated after (relative to the direction of flow 11) its interaction zone 14 and comprising a flame 26 resulting from the interaction between the reagent and the
beam 3 in its interaction zone 14.
- an interaction zone 14 with the
- The
beam 3 is shaped by an optical system to give it a cross-section that is preferably rectangular (but could also be elliptical) and preferably focused vertically (i.e. the area of which decreases with the advance of thebeam 3 in the direction of radiation 12), as described indocuments FR 2 894 493 andFR 2 877 591. - The
beam 3 enters thechamber 8 through awindow 23 of ZnSe and leaves thechamber 8 through anotherwindow 24 of ZnSe before being stopped by a non-reflective calorimeter 25 (“beam stopper”). - The
device 9 further comprises a source of a second chemical element. The second chemical element is preferably aluminium injected in the form of trimethylaluminium (or TMA, of chemical formula Al(CH3)3, or generally in the form of a compound in the class of aluminium organometallics) heated and vaporized preferably in a neutral gas, such as for example argon. An injector of a second element is arranged in order to introduce, into thereaction chamber 8, the second chemical element from the source of second element so that this second chemical element is able to interact in thechamber 8 with eachreaction stream particle cores 15 with alayer 16 comprising the second chemical element. - Preferably, the reagent in the
source 4 and injected intochamber 8 is devoid of oxidizing agent arranged for oxidizing the first chemical element. By “agent arranged for oxidizing the first chemical element” (also called “oxidizing agent of the first chemical element”) is meant any atom or molecule (for example N2O) which, in the reagent (for example SiH4 gas, optionally mixed with C2H2 or C2H4 or CH4), has a redox potential with tendency for oxidation of the first chemical element (for example Si) due to the form (for example SiH4) in which it is injected into thechamber 8. Preferably, the reagent in thesource 4 and injected into thechamber 8 is devoid of oxygen atoms. - The injector (5, 21 and/or 22) of the second element and the
injector 5 of the first element are arranged together within the device 9 (by their flow rate and their proportions of the various gases, optionally mixed, that they deliver, such as SiH4 for theinjector 5, argon or nitrogen for theinjector 21 and C2H2, C2H4, CH4 for theinjector 5 and/or 21 and/or 22) in order to introduce into thereaction chamber 8 per unit of time (typically per minute) a number of atoms of the second element relative to a number of atoms of the first element according to a ratio selected for reaching the desired thickness of thelayer 16. - Typically, the injector (5, 21 and/or 22) of the second element and the
injector 5 of the first element are arranged together within thedevice 9 in order to introduce the desired molar ratio between the second and the first element. - For example, to produce particles having a core diameter D1 and a diameter D2 of the layer comprising the second chemical element, the following relationship is used:
-
- where:
- n1 is the number of atoms constituting the
particle core 15, introduced into the reaction chamber (preferably only in at least one reaction stream) per unit of time. For example: -
- in the case of a core of pure silicon, it is the number nsi of silicon atoms introduced into the reaction chamber per unit of time (preferably only in at least one reaction stream),
- in the case of a “mixed” core such as of silicon carbide, it is the number nsi of silicon atoms introduced into the reaction chamber per unit of time (preferably only in at least one reaction stream) plus the number nc of carbon atoms introduced into the reaction chamber per unit of time (preferably only in the at least one reaction stream), for example assuming nsi=nc.
- d1 is the density of the material (for example pure silicon, or pure silicon carbide) constituting the
core 15 of the particles, - M1 is the molecular weight of the material (for example pure silicon or silicon carbide) making up the
core 15 of the particles, - V1 is the desired volume for a
particle core 15 of diameter D1, approximately equal to -
- n2 is the number of atoms constituting the
layer 16, introduced (in the sum of the reaction streams 1, 100, 101, 102, 103, 104, 105, 106, the confiningstream 2 and optionallyperipheral streams 7 if they are present) into the reaction chamber per unit of time. For example: -
- in the case of a
layer 16 of pure aluminium, it is the number nAl of aluminium atoms introduced into the reaction chamber per unit of time,
- in the case of a
- d2 is the density of the material (for example pure aluminium or oxidized aluminium) constituting the
layer 16, - M2 is the molecular weight of the material (for example pure aluminium or oxidized aluminium) constituting the
layer 16, - V2 is the desired volume for a
layer 16, approximately equal to -
- The
device 9 further comprises asource 20 of confining gas comprising confining gas and aninjector 21 of confining gas arranged in order to introduce into thereaction chamber 8, before (relative to the direction of flow 11) the interaction zone 14 of each reaction stream, a confining gas stream 2 (preferably common to all the reaction streams) surrounding eachreaction stream reaction stream reaction stream chamber 8 up to the interaction zone 14 of each reaction stream, this perimeter being defined according to a closed line contained in a plane perpendicular to the direction of flow 11) and propagating in the direction offlow 11. - The confining gas comprises a neutral gas (from helium, argon, nitrogen or a mixture thereof, preferably argon or nitrogen). The confining
gas stream 2 has two functions: -
- on the one hand, it serves to confine each reaction stream to prevent the reagents of each reaction stream diffusing radially, with the risk of soiling the inner walls of the
chamber 8, and - on the other hand, it serves to cool (“quench effect”) each flame 26 of reaction stream created after (relative to the direction of flow 11)
- the interaction of the
beam 3 with eachreaction stream
- on the one hand, it serves to confine each reaction stream to prevent the reagents of each reaction stream diffusing radially, with the risk of soiling the inner walls of the
- The
emitter 19 is arranged so that theradiation beam 3 propagates in a direction ofradiation 12 perpendicular to the direction offlow 11. - The
injector 5 of at least onereaction stream reaction stream flow 11, a section that may extend longitudinally in a direction ofelongation 13 perpendicular to the direction offlow 11 and to the direction ofradiation 12. - In a first variant of the first embodiment of the
device 9, which may correspond to the sectional view inFIG. 2 , thereagent injector 5 is arranged in order to introduce into thechamber 8, and originating from thereagent source 4, asingle reaction stream 1 that propagates in the direction offlow 11 in areaction stream zone 6. The cross-section of theinjector 5 is typically an oval with a depth of 4 mm in thedirection 12 and a width of 2 cm in thedirection 13. - In a second variant of the first embodiment of the
device 9, which may correspond to the cross-section side view inFIG. 2 and the cross-section front view inFIG. 3 , theinjector 5 of at least one reaction stream is arranged in order to introduce, into thechamber 8 and originating from thereagent source 4, an alignment of several reaction streams 101, 102, 103 separated from one another by the confininggas stream 2 and each comprising the first chemical element and each propagating in the direction offlow 11. - Each
stream flow 11 in its ownreaction stream zone 6. - The
injector 5 of at least onereaction stream streams alignment 18 perpendicular to the direction offlow 11 and to the direction ofradiation 12. - As shown in
FIG. 3 , theinjector 5 is subdivided intoseveral injection nozzles direction 12 and with width of 4 mm in thedirection nozzles - In a third variant of the first embodiment of the
device 9, which may correspond to the cross-section side view inFIG. 4 and the perspective view inFIG. 5 , theinjector 5 of at least one reaction stream is arranged in order to introduce, into thechamber 8,several reaction streams gas stream 2 and each comprising the first chemical element and each propagating in the direction offlow 11. - The
reagent injector 5 is arranged in order to introduce, into thechamber 8 and originating from thereagent source 4,several reaction streams stream flow 11 in its ownreaction stream zone 6. Thesestreams radiation 12. - The losses of the
beam 3 by absorption by thereaction stream 1 are compensated by the focusing (or “convergence”) of thebeam 3 so that the incident power density of thebeam 3 on eachstream streams document FR 2 877 591. - This variant makes it possible to increase the rate of production on a single reactor with optimum consumption of laser energy for production. There may be two
streams FIG. 5 , or there may be 3, 4 or even more one after another, arranged in a row with asingle laser beam 3. - In a fourth variant of the first embodiment of the
device 9, which may correspond to the cross-section side view inFIG. 4 and the perspective view inFIG. 6 , theinjector 5 of at least one reaction stream is arranged in order to introduce, into thechamber 8 and originating from thereagent source 4, several alignments of reaction streams separated from one another by the confininggas stream 2 and each comprising the first chemical element and each propagating in the direction offlow 11. -
FIG. 6 shows a first alignment ofstreams streams - Each
stream flow 11 in its ownreaction stream zone 6. - The
injector 5 of at least one reaction stream is arranged so that thestreams alignment 18 perpendicular to the direction offlow 11 and to the direction ofradiation 12. - The alignments of streams are spaced apart in the direction of
radiation 12. - The various alignments of streams are parallel to one another in the
same direction 18. - The
injector 5 is subdivided into several injection nozzles (one nozzle per reaction stream). Each nozzle has a cross-section that is typically an oval with a depth of 3 mm in thedirection 12 and with a width of 4 mm in thedirection - The losses of
beam 3 by absorption by the first alignment ofstreams beam 3 so that the incident power density of thebeam 3 on each alignment ofstreams streams document FR 2 877 591. - Referring to
FIGS. 1 to 6 , in the first embodiment of thedevice 9 according to the invention (whatever variant thereof is considered from its four variants described above), the injector of the second chemical element is arranged in order to introduce the second element into thechamber 8 with the first chemical element in eachreaction stream - The injector of the second chemical element comprises the
reagent injector 5. More precisely, the injector of the second chemical element and thereagent injector 5 are combined. - Referring to
FIGS. 1 to 6 , a second embodiment of thedevice 9 according to the invention is strictly identical to the first embodiment of thedevice 9 described above (whatever variant is considered from its four variants described above), apart from the fact that the injector of the second chemical element is arranged in order to introduce the second chemical element into thechamber 8 in agas stream 2 surrounding eachreaction stream - More precisely, the injector of the second chemical element is arranged in order to introduce the second chemical element into the
chamber 8 in the confininggas stream 2 before (relative to the direction of flow 11) the interaction zone 14 of each reaction stream. - The injector of the second chemical element comprises the
injector 21 of confining gas. More precisely, the injector of the second chemical element and theinjector 21 of confining gas are combined. - This second embodiment is preferably implemented within the second or fourth variant (comprising one or more alignment(s) of
streams FIGS. 3 and 6 ) as this makes it possible to maximize the area of interaction between the confininggas 2 comprising the second chemical element and each reaction stream comprising the first chemical element. - Referring to
FIGS. 2 to 8 , a third embodiment of thedevice 9 according to the invention is strictly identical to the first embodiment of thedevice 9 described above (whatever variant is considered from its four variants described above), apart from the fact that the injector of the second chemical element is arranged in order to introduce the second chemical element into thechamber 8 in agas stream 7 surrounding eachreaction stream - The injector of the second chemical element comprises an injector 22 (preferably of annular shape):
-
- per
reaction stream - common, surrounding all the reaction streams overall.
- per
- For each reaction stream considered 1, 100, 101, 102, 103, 104, 105, or 106, the injector of the second chemical element is arranged in order to introduce the second chemical element into the
chamber 8 in aperipheral gas stream 7 surrounding thisreaction stream several points 17 distributed along a closed curve (typically annular shape of injector 22) surrounding this reaction stream and arranged in order to direct theperipheral gas stream 7 in the direction of this reaction stream. - For each reaction stream considered 1, 100, 101, 102, 103, 104, 105, or 106, the injector of the second chemical element is arranged in order to introduce the second chemical element into the
chamber 8 in theperipheral gas stream 7 after (relative to the direction of flow 11) the interaction zone 14 of this reaction stream. This is particularly beneficial, as it makes it possible to have good control (by adjusting the power of the beam 3) and good uniformity of manufacture of thecores 15 of theparticles 10. Manufacture of thelayers 16 on thecores 15 of the particles will not take energy directly from thebeam 3 and therefore does not disturb the control of the manufacture of thecores 15. In fact, manufacture of thelayers 16 on theparticle cores 15 utilizes the energy of the flame 26 after the interaction zone 14. - This third embodiment of the
device 9 comprises means for moving (not shown, comprising for example a micro-displacement stage) eachinjector 22 in the direction offlow 11 so as to optimize thelayer 16 manufactured for theparticles 10. - Of course, the different variants and the different embodiments of the device according to the invention that have just been described may be combined with one another, and the injector of the second chemical element may therefore comprise:
-
- the
reaction stream injector 5, and/or (preferably and) - at least one (optionally both) of:
- the confining
gas injector 21 of, and/or - an
injector 22 ofperipheral gas 7 per reaction stream or acommon injector 22 ofperipheral gas 7 surrounding all the reaction streams overall.
- the confining
- the
- A description will now be given of the process implemented in any one of the embodiments of the
device 9 that has just been described. - This process according to the invention for producing
particles 10 by laser pyrolysis comprises the following steps: -
- introducing into the
reaction chamber 8, via theinjector 5 and originating from thesource 4, at least onereaction stream flow 11; each reaction stream comprises reagent during its introduction; the typical gas flow rate of reagent introduced into thechamber 8 is about 20 litres per minute. - introducing into the
reaction chamber 8, before (relative to the direction of flow 11) the interaction zone 14 of each reaction stream, the confininggas stream 2 surrounding eachreaction stream flow 11; the typical flow rate of confining gas introduced into thechamber 8 is about 50 litres per minute. - projecting, by the
emitter 19, theradiation beam 3 through thereaction chamber 8 at intersection, in one interaction zone 14 per reaction stream, with eachreaction stream particle cores 15 comprising the first chemical element, and - introducing, into the
reaction chamber 8, the second chemical element interacting with eachreaction stream particle cores 15 with a layer 16 (corresponding to eachparticle 10 and independent of thelayer 16 of the other particles 10) comprising the second chemical element.
- introducing into the
- As seen above, the reagent of the reaction stream is devoid of agent that oxidizes the first chemical element. Thus, the
particle cores 15 obtained by the process according to the invention comprise the first chemical element in the non-oxidized form. - The number of atoms introduced per unit of time is in a molar ratio allowing the desired thickness to be attained for producing a
layer 16 of aluminium or of aluminium oxide obtained by oxidation of the layer of aluminium. - The
radiation beam 3 propagates in the direction ofradiation 12 perpendicular to the direction offlow 11. - Each reaction stream has, in a plane perpendicular to the direction of
flow 11, a section extending longitudinally in the direction ofelongation 13 perpendicular to the direction offlow 11 and to the direction ofradiation 12. - The
particles 10 thus manufactured drop into arecovery device 27 where they are cooled before being conveyed by gravity and/or vacuum to a plant that uses the particles or to a container for storage. - In a first embodiment of the process according to the invention implemented in the first embodiment of the device according to the invention, the second chemical element is introduced into the
chamber 8 with the first chemical element in the reagent in eachreaction stream - In a second or third embodiment of the process according to the invention implemented in the second or third embodiment of the device according to the invention, the second chemical element is introduced into the
chamber 8 in agas stream reaction stream reaction stream - In a second embodiment of the process according to the invention implemented in the second embodiment of the device according to the invention, the second chemical element is introduced into the
chamber 8 in the confininggas stream 2 before (relative to the direction of flow 11) the interaction zone 14 of each reaction stream. - This embodiment is particularly beneficial when, as described above with reference to
FIG. 3 or 6 , the introduction of at least one reaction stream comprises an introduction of several aligned reaction streams (alignment addition alignment gas stream 2 and each comprising the first chemical element and each propagating in the direction offlow 11. It should be noted that in that case, as shown inFIG. 3 , the confininggas stream 2 is preferably common to all the reaction streams and there is no discontinuity between the various reaction streams. Moreover, theradiation beam 3 propagates in the direction ofradiation 12 perpendicular to the direction offlow 11, and the various reaction streams 101, 102, 103 or 104, 105, 106 within an alignment are aligned in the direction ofalignment 18 perpendicular to the direction offlow 11 and to the direction ofradiation 12. - In a third embodiment of the process according to the invention implemented in the third embodiment of the device according to the invention, the second chemical element is introduced into the
chamber 8 in aperipheral gas stream 7 surrounding eachreaction stream several points 17 distributed along a closed curve surrounding each reaction stream and propagating in the direction of the reaction stream. The second chemical element is introduced into thechamber 8 in theperipheral gas stream 7 after (relative to the direction of flow 11) the interaction zone 14 of each reaction stream. - Thus, to summarize what each of the streams generally contains:
-
- each
reaction stream - in all cases, a type of molecule comprising the first chemical element. In the case when this first chemical element is silicon, this molecule is preferably a silicon-based organometallic (generally in the form of vaporized liquid). This molecule may for example be hexamethyldisilazane. This molecule may also for example be silane (SiH4).
- Optionally, if the
core 15 is of silicon carbide, a type of molecule comprising carbon, for example an alkene or an alkane. This molecule may for example be C2H2 or C2H4 or CH4. - Optionally a neutral gas or a mixture of neutral gases from helium, argon, krypton, xenon, nitrogen.
- Optionally, in the first embodiment of the process according to the invention, a type of molecule comprising aluminium. This molecule may for example be vaporized trimethylaluminium (Al(CH3)3). In general, a compound in the class of aluminium organometallics may be used.
- each confining
gas stream 2 comprises (preferably consists only of):- in all cases, a neutral gas or a mixture of neutral gases from helium, argon, krypton, xenon, nitrogen.
- Optionally, in the second embodiment of the process according to the invention, a type of molecule comprising the second chemical element. This molecule may for example be vaporized trimethylaluminium (Al(CH3)3). In general, a compound in the class of aluminium organometallics may be used.
- each
peripheral gas stream 7, present only in the third embodiment of the process according to the invention, comprises (preferably consists only of):- in the third embodiment of the process according to the invention, a type of molecule comprising the second chemical element. This molecule may for example be vaporized trimethylaluminium (Al(CH3)3). In general, a compound in the class of aluminium organometallics may be used.
- Optionally a neutral gas or a mixture of neutral gases from helium, argon, krypton, xenon, nitrogen.
- each
- Of course, various combinations of processes according to the invention described above may be envisaged, in which the second chemical element is introduced into the chamber 8:
-
- with the first chemical element in each
reaction stream - in a
gas stream reaction stream reaction stream - in the confining
gas stream 2, and/or - in one
peripheral gas stream 7 per reaction stream or in a commonperipheral gas stream 7 surrounding all the reaction streams overall.
- in the confining
- with the first chemical element in each
- In this example, the first chemical element is silicon.
- The second chemical element is pure aluminium, which may be oxidized after production.
- The laser used is a CO2 laser, the surface density of incident energy is 800 W per square centimetre.
- The first chemical element is introduced at ambient temperature (approximately 20° C.) into the
chamber 8 in the form of gaseous SiH4, at approximately 18 litres per minute of gaseous SiH4. - The reagent of each reaction stream is thus gaseous silane (SiH4) that is not mixed with oxidizing agents or with oxygen atoms or with molecules comprising oxygen atoms, so that the
particle cores 15 comprise (and even preferably consist of), preferably non-oxidized, silicon (Si). - The confining
gas 2 comprises a neutral gas (gaseous argon) introduced into thechamber 8 at ambient temperature at 50 litres per minute. - The second chemical element is introduced into the reaction chamber in the form of trimethylaluminium (or TMA, of chemical formula Al(CH3)3) or generally in the form of a compound in the class of aluminium organometallics. It is introduced into the chamber at a temperature of 50° C. in the
peripheral gas stream 7, which also carries neutral argon gas. The total gas flow rate Argon+TMA is 33 litres per minute gaseous. - The number of aluminium atoms introduced (which plays the role of the second element here) relative to the number of atoms of the first element (silicon) introduced is a ratio of one aluminium atom to 3.7 silicon atoms (1 mole of Al(CH3)3 to 3.7 moles of SiH4).
- The
layer 16 of each particle thus obtained is of non-oxidized aluminium. - At the outlet of the recovery device, the
particles 10 are optionally: -
- protected from oxygen or generally from oxidation until they are stored (preferably in a container not integral with the chamber 8), so that the
layer 16 of each particle thus stored is still non-oxidized aluminium, or - subjected to slow oxidation so that the
layer 16 of aluminium (but not the core 15) of each particle is oxidized.
- protected from oxygen or generally from oxidation until they are stored (preferably in a container not integral with the chamber 8), so that the
- The particles obtained may then be used, by various processes including:
-
- a process that is characterized in that a component is manufactured by sintering a powder comprising these particles (typically heating at 1000° C.), and/or
- a process in which aluminium particles are mixed with particles according to the invention having a core 15 covered with a
layer 16 of aluminium, then in which the mixture is heated (typically at 1000° C.) and then cooled so as to bond the aluminium particles with the particles according to the invention, in order to obtain a material of aluminium enriched with what constitutes thecore 15 of the particles according to the invention.
- Example 2 will only be described where it differs from example 1. Example 2 is identical to example 1, except that in example 2 the surface density of incident energy is 1500 W per square centimetre and the reagent in each reaction stream is a mixture of:
-
- gaseous silane (SiH4) not mixed with oxidizing agents or with oxygen atoms or with molecules comprising oxygen atoms, and
- gaseous C2H2 not mixed with oxidizing agents or with oxygen atoms or with molecules comprising oxygen atoms so that the
particle cores 15 comprise (preferably consist of) silicon carbide (SiC), preferably not oxidized.
- Particles Obtained
- Particles according to the first example were manufactured according to example 1 and example 2 with the third embodiment of
device 9 alone (i.e. with the third embodiment of the process according to the invention). They are subjected to slow oxidation at the end of production so as to generate a layer of aluminium oxide. - The size of the
particles 10 obtained corresponds to an average core diameter D1 determined from measurement of the specific surface and density: -
- of 100 nm in example 1 and
- of 30 nm in example 2,
and a thickness of layer 16 (half of D2−D1) of aluminium oxide of about 3-10 nm thick.
- By transmission electron microscopy techniques, it is possible to see particles 10 (often combined in solid aggregates and/or agglomerates owing to interactions of the van der Waals type between the particles). The homogeneity of the
layer 16 is excellent (for example by comparison betweenFIGS. 9 and 10 ) using the third embodiment of the process according to the invention, in which the second chemical element is introduced into thechamber 8 in agas stream 7 surrounding eachreaction stream reaction stream FIG. 10 , for each particle 10 alayer 16 of almost uniform thickness is obtained, which covers the whole of itscore 15. The particles are almost spherical, and are reminiscent of faceted balls. -
FIG. 11 is a graph of detection of chemical elements by STEM/EELS techniques of transmission electron microscopy, as a function (on the x-axis) of the position along a segment starting from acore 15 of a particle and continuing over thelayer 16 of this same particle and then to the exterior of this particle. The y-axis shows intensity related to the proportion of the elements detected. - In the
layer 16, aluminium and oxygen are detected, but not carbon or silicon. - In the
core 15, silicon and carbon are detected. - At the level of the core 15, a small quantity of aluminium and oxygen is also detected, due to the fact that the imaged zone of
core 15 is superimposed on thelayer 16. In fact it is a profile obtained by moving an analysis probe along an axis situated above the particle, and when the probe moves over the core 15 this leads to superposition of the majority signals from the core and the minority signals from the surface. - It can be seen that in example 1 and example 2, the
layer 16 does not comprise the first chemical element (in any form). - It can be seen that in example 1 and example 2, the
core 15 does not comprise the first chemical element in the oxidized form, but comprises this first chemical element only in the non-oxidized form. - The third embodiment of the invention is therefore preferred for several reasons:
-
- better homogeneity of the
layer 16, - better control and homogeneity of the
cores 15.
- better homogeneity of the
- Better results are seen from the third embodiment alone than from the second and first embodiment alone.
- For comparison, on modifying the first and second examples in the context of the second embodiment of the process according to the invention, poorer control of the
core 15 is noted, and problems of homogeneity. In particular, it can be seen thatcertain cores 15 additionally comprise the second chemical element (traces of aluminium), and the existence of particles consisting of aluminium is noted. - For comparison, on modifying the first and second examples in the context of the first embodiment of the process according to the invention, additional problems of homogeneity are observed.
- Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without exceeding the scope of the invention.
- In particular, the examples and embodiments described above are not incompatible with the existence of an interface between the core 15 and the
layer 16 of one and the same particle. - Of course, the various features, forms, variants and embodiments of the invention may be combined together in various combinations provided they are not incompatible or exclusive of one another. In particular, all the variants and embodiments described above can be combined.
Claims (29)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR1361856A FR3013991B1 (en) | 2013-11-29 | 2013-11-29 | SUBMICRONIC PARTICLES COMPRISING ALUMINUM |
FR1361856 | 2013-11-29 | ||
PCT/EP2014/076021 WO2015079050A1 (en) | 2013-11-29 | 2014-11-28 | Submicron-sized particles including aluminum |
Publications (2)
Publication Number | Publication Date |
---|---|
US20160376158A1 true US20160376158A1 (en) | 2016-12-29 |
US10227236B2 US10227236B2 (en) | 2019-03-12 |
Family
ID=50976683
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/039,824 Expired - Fee Related US10227236B2 (en) | 2013-11-29 | 2014-11-28 | Method for producing submicron-sized particles including aluminum by laser treatment |
Country Status (4)
Country | Link |
---|---|
US (1) | US10227236B2 (en) |
EP (1) | EP3074469B1 (en) |
FR (1) | FR3013991B1 (en) |
WO (1) | WO2015079050A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20170081198A1 (en) * | 2014-03-06 | 2017-03-23 | Taizhou Beyond Technology Co., Ltd. | A Production Process for Silicon Carbide |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20050016839A1 (en) * | 2003-06-06 | 2005-01-27 | Horne Craig R. | Reactive deposition for electrochemical cell production |
US20150299861A1 (en) * | 2012-11-26 | 2015-10-22 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Device for Synthesising Core-Shell Nanoparticles by Laser Pyrolysis and Associated Method |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4424066A (en) * | 1982-05-20 | 1984-01-03 | Gte Laboratories Incorporated | Alumina coated composite silicon aluminum oxynitride cutting tools |
US4505720A (en) * | 1983-06-29 | 1985-03-19 | Minnesota Mining And Manufacturing Company | Granular silicon carbide abrasive grain coated with refractory material, method of making the same and articles made therewith |
US5874134A (en) * | 1996-01-29 | 1999-02-23 | Regents Of The University Of Minnesota | Production of nanostructured materials by hypersonic plasma particle deposition |
WO2001032799A1 (en) * | 1999-11-04 | 2001-05-10 | Nanogram Corporation | Particle dispersions |
FR2877591B1 (en) | 2004-11-09 | 2007-06-08 | Commissariat Energie Atomique | SYSTEM AND PROCESS FOR PRODUCING CONTINUOUS FLOW OF NANOMETRIC OR SUB-MICROMETRIC POWDERS UNDER LASER PYROLYSIS |
EP1760045A1 (en) * | 2005-09-03 | 2007-03-07 | Degussa GmbH | Nanoscale silicon particles |
FR2894493B1 (en) | 2005-12-08 | 2008-01-18 | Commissariat Energie Atomique | SYSTEM AND PROCESS FOR PRODUCING CONTINUOUS FLOW OF NANOMETRIC OR SUB-MICROMETRIC POWDERS UNDER LASER PYROLYSIS |
DE102006038518A1 (en) * | 2006-08-17 | 2008-02-21 | Evonik Degussa Gmbh | Enveloped zinc oxide particles |
US20090026421A1 (en) * | 2007-01-22 | 2009-01-29 | Xuegeng Li | Optimized laser pyrolysis reactor and methods therefor |
-
2013
- 2013-11-29 FR FR1361856A patent/FR3013991B1/en not_active Expired - Fee Related
-
2014
- 2014-11-28 US US15/039,824 patent/US10227236B2/en not_active Expired - Fee Related
- 2014-11-28 WO PCT/EP2014/076021 patent/WO2015079050A1/en active Application Filing
- 2014-11-28 EP EP14816143.3A patent/EP3074469B1/en active Active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20050016839A1 (en) * | 2003-06-06 | 2005-01-27 | Horne Craig R. | Reactive deposition for electrochemical cell production |
US20150299861A1 (en) * | 2012-11-26 | 2015-10-22 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Device for Synthesising Core-Shell Nanoparticles by Laser Pyrolysis and Associated Method |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20170081198A1 (en) * | 2014-03-06 | 2017-03-23 | Taizhou Beyond Technology Co., Ltd. | A Production Process for Silicon Carbide |
US10407307B2 (en) * | 2014-03-06 | 2019-09-10 | Taizhou Beyond Technology Co., Ltd. | Production process for silicon carbide |
Also Published As
Publication number | Publication date |
---|---|
US10227236B2 (en) | 2019-03-12 |
FR3013991B1 (en) | 2019-04-26 |
EP3074469B1 (en) | 2018-10-17 |
EP3074469A1 (en) | 2016-10-05 |
FR3013991A1 (en) | 2015-06-05 |
WO2015079050A1 (en) | 2015-06-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Adhikari et al. | Progress in powder coating technology using atomic layer deposition | |
Gröhn et al. | Scale-up of nanoparticle synthesis by flame spray pyrolysis: the high-temperature particle residence time | |
US8986602B2 (en) | Multiple feeder reactor for the production of nano-particles of metal | |
Wei et al. | Quantum‐Sized Metal Catalysts for Hot‐Electron‐Driven Chemical Transformation | |
Jossen et al. | Criteria for flame‐spray synthesis of hollow, shell‐like, or inhomogeneous oxides | |
KR101129610B1 (en) | Induction plasma synthesis of nanopowders | |
US20120048064A1 (en) | Multi mode production complex for nano-particles of metal | |
US6919054B2 (en) | Reactant nozzles within flowing reactors | |
JP5038327B2 (en) | System and method for continuous flow generation of nano or submicron powders by the action of laser pyrolysis | |
Wu et al. | Structure and chemical transformation in cerium oxide nanoparticles coated by surfactant cetyltrimethylammonium bromide (CTAB): an X-ray absorption spectroscopic study | |
US10611643B2 (en) | Method for producing multilayer submicron particles by laser pyrolysis | |
Hirano et al. | Tubular flame combustion for nanoparticle production | |
US10227236B2 (en) | Method for producing submicron-sized particles including aluminum by laser treatment | |
Gschwend et al. | 110th Anniversary: Synthesis of Plasmonic Silica-Coated TiN Particles | |
Sudheeshkumar et al. | Thermal stability of alumina-overcoated Au25 clusters for catalysis | |
Gonzalez-Martinez et al. | Room temperature in situ growth of B/BO x nanowires and BO x nanotubes | |
Fleaca et al. | Laser oxidative pyrolysis synthesis and annealing of TiO2 nanoparticles embedded in carbon–silica shells/matrix | |
Chen et al. | Efficient and green synthesis of SiOC nanoparticles at near-ambient conditions by liquid-phase plasma | |
CN101242894B (en) | Photocatalyst | |
JP4932718B2 (en) | Method for producing metal powder | |
Ferrah et al. | A Photoemission Analysis of Gold on Silicon Regarding the Initial Stages of Nanowire Metal-Catalyzed Vapor–Liquid–Solid Growth | |
Liu et al. | Preparation of highly flexible SiC nanowires by fluidized bed chemical vapor deposition | |
Zambov et al. | Template‐Directed CVD of Dielectric Nanotubes | |
Oshima et al. | Analysis of Fe catalyst during carbon nanotube synthesis by Mossbauer spectroscopy | |
Dasgupta | Studies on the synthesis and in-line coating of nanoparticles from the gas phase |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: NANOMAKERS, FRANCE Free format text: EMPLOYMENT AGREEMENT;ASSIGNORS:REAU, ADRIEN;TENEGAL, FRANCOIS;SIGNING DATES FROM 20110309 TO 20111004;REEL/FRAME:041098/0804 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
LAPS | Lapse for failure to pay maintenance fees |
Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20230312 |